Screw jack



' Oct- 5,1926. 1,601,890

7 F. w. STORK SCREW JACK Filed August 5, 1925 Fly/4. M

ATTORNEY Patented get. 5, 19.2 5

UNITED stares I I 1,601,8Sit ENT OFFICE.

VT.STORK, OF SAG-INAW,-MICHIGAN, .ASSIGNOR TO STORK ENGIIIEERING ANDMANUFACTURING COMPANY, OF SAGINAXV, MICHIGAN, A GQE'EGRA'ZZUH GE MICE?GAN.

SCREW JACK.

Application filed. August 3, 1925. Serial Ho. 47,849."

This invention relates to screw jacks for The objectsare to provide, inconjunction,

with a compact gear case, a pair of oppositely disposed removable coversthat are secured to the sides of the base by a through bolt, which isarranged so as to permit easy removal and replacement of the covers foraccess to the gears, and also acts as a gear retaining device, keepingthe gear from tilting upward or ten-ding to climb the rectangularscrew-operating shaft when the jack is in operation. 7

By means of the through bolt the actuating gear is always kept in propermeshing relation to the pinion by which the gear is rotated.

With the foregoing and certain other objects in view, which will appearlater in the specifications, my invention comprises the devicesdescribed and claimed and the equivalents thereof.

Fig. 1 is a side view of a screw jack embodying my improvement.

Fig. 2 is a part sectional side view of the base, showing the screwactuating gear and pinion, the jack screw being in its lowered position.

Fig. 3 is a perspective view of a pair of oppositely disposed removablecover plates for the sides of the base, the plates connected by a-boltarranged and operating in accordance with my invention.

Fig. d is'a part sectional detail of the gear, and the square shaft uponwhich the jack screw travels up and down, the screw shown in itsextended position.

As is clearly shown in the drawings, the device is applied to the body 1of a screw jack, tl e base of which is made in the form of a gear caseopen at the sides.

Numeral 2 indicates the usual crank-re-j ceiving socket in the hub ofthe operating pinion. The jack screw 3, as is customary in this class ofimplements, is slidable up and down on a square central shaft, the shaftbeing rotated by the gear. lVhen the screw is retracted its lower end 3rests upon the gear and when it is raised, as shown inFig. 4:, its lowerend is clear of the gear.

My present improvement relates particularly to a simple and novel means,namely,

the gear case cover 4-, 4 and the through bolt 5, by which the gear 6 iskept from tilting when the screw 3 is not in contact with the gear, asshown in Fig. f. The gear is turned by the usual pinion 7, preferably bya suitable handle engaging the socket 2. The upright central shaft 8 ispreferably secured to and is driven by gear 6. It turns the crew 3 whenthe jack is in operation, the function and more of operation of thescrew being that of the ordinary screw jack.

When the covers 4, 4 are removed the en tire interior of the base,including the gears and the end of the screw, are opened for inspection.place and held by bolt 5, shown in Fig. 1, and the screw 3 is raisedclear of the gear 6, as shown in Fig. 4, the bolt 5 effectually preventsany tendency for the gear 6 to tilt and thus disturb the proper runningalign ment of the gear and pinion 7 The bolt 5 is, as shown, locatedabove and in proximity to the upper face of the gear and opposite thepinion 7 By this means there is no tendency for the jack when under loadto bind and operate with difliculty, as would be the case when gear 6 isnot provided with means for preventing tilting,

and the means herein shown, namely, the bolt 5 mounted 1n the covers 4,4' is a simple,

yet effective device for accomplishing this result, and one that doesnot interfere with the removal or replacement of the working parts ofthe jack. The working parts of this jack can be assembled rapidly andcheaply when produced in large quantities, because the gear 6 and pinion7 can be in serted in the base by merely dropping them into place fromeither .side, then when the covers 4, 4t are placed the bolt 5 becomes ialso a gear-retaining element.

In the foregoing description and in the drawings I have set forth andillustrated my invention as constructed with two removable covers, thisbeing the preferred con struction, It would .be possible, however, andin some cases possibly advisable, to make the jack with one of thecovers not removable, that is to say, either permanently fixed or castintegral with the side of the gear case. The construction and mode ofoperation of the other cover and the through bolt would, however, be thesame in both arrangements. Therefore, I desire it to be understood thata single removable cover 1 l Vhen the covers 4, a are in ieo and thethrough bolt 5 may be employed if desired, Without departing from thespirit or" my invention as herein set forth and claimed,

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. In a screw jack, a body, the base of which comprises a gear case, ascrew arranged to operate in said body, a gear and a co-acting pinion insaid case, a pair of oppositely disposed removable gear case covers, abolt extending through the base and connecting said covers, that partofsaid bolt within the base being located in proximity to the upper faceof the gear and opposite the pinion whereby said bolt serves to retainsaid gear in operating relation to said p1n1on.

2. In a screw jack, a body, the base of which comprises a gear case, ascrew arranged to operate in sai-d'body, a gear and a co-acting pinionin said case, a removable gear case cover, a bolt extending through thebase and connecting said cover with the opposite wall or" said case,that part of said bolt within the base being located in proximity to theupper face of the gear and opposit-e the pinion, whereby said boltserves to retain said gear in operating relation to lie said pinion.

In testimony whereof, I afiix my signature.

FRED W. STORK.

